Diodes Incorporated 74HCT594S16-13

Overview

74HCT594S16-13 from Diodes Incorporated is an 8-bit serial-in, parallel-out shift register with separate 8-bit storage register and serial output (Q7S), implemented in high-speed HCMOS technology. It operates from 4.5 V to 5.5 V, features Schmitt-trigger inputs, supports 8 mA output drive at V_CC = 4.5 V, and delivers up to 92 MHz shift clock frequency at V_CC = 5 V. It is used in microcontroller-based peripheral expansion where serial bit streams control multiple parallel outputs.

For engineers reviewing the 74HCT594S16-13 datasheet, 74HCT594S16-13 pinout, 74HCT594S16-13 application, or 74HCT594S16-13 equivalent, this device serves as a timing-critical serial-to-parallel interface with independent shift/storage register clocks, active-low asynchronous resets, and push-pull outputs suitable for LED drivers, address latching, and cascaded I/O expansion.

Technical Context

The 74HCT594 integrates two synchronized but independently clocked registers: an 8-bit shift register accepting data on DS at each rising edge of SHCP, and an 8-bit storage register loaded on rising STCP. Both SHR and STR are active-low asynchronous resets, independent of clock states.

All outputs (Q0–Q7) are push-pull with guaranteed VOH ≥ 3.7 V at I_OH = −6 mA and VOL ≤ 0.4 V at I_OL = 6 mA (V_CC = 4.5 V). Q7S provides cascading capability with propagation delay ≤ 48 ns (CL = 50 pF, TA = −40°C to +125°C).

Key Specifications

Pinout & Package

74HCT594S16-13 is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, JEDEC MS-012 compliant, body dimensions 10.0 × 4.0 × 1.75 mm, and gull-wing leads for reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial-to-parallel shift register applications.

Compared with SN74HC595PWR and 74LV595PW,118, the 74HCT594S16-13 uniquely combines independent asynchronous resets, Schmitt-trigger noise immunity, and Q7S cascading - making it optimal for deterministic, noise-resilient I/O expansion in industrial control.

Availability

74HCT594S16-13 is available at Aetrix Electronics and suitable for LED display drivers, microcontroller I/O expansion, industrial address latching, and appliance control panel interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT594S16-13 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-reliability power management, signal integrity, and logic solutions for industrial, computing, and consumer markets.

The 74HCT594 belongs to Diodes' HCT logic family, engineered for pin compatibility with legacy 74LS devices while delivering CMOS power efficiency and enhanced noise immunity - targeting upgrade paths in legacy 5 V systems.

FAQ

Can 74HCT594S16-13 operate reliably at 125°C junction temperature?

Yes. The device is fully characterized from −40°C to +125°C ambient temperature, with all electrical parameters (including t_PD, f_MAX, and VOH/VOL) specified across this range. Its maximum junction temperature rating is +150°C, providing 25°C thermal margin under typical PCB power dissipation.

What is the function of Q7S versus Q7, and how do they differ electrically?

Q7 is the parallel output of the storage register stage 7, updated only on STCP rising edge. Q7S is the serial output of the shift register stage 7, updated on SHCP rising edge and usable for cascading. Electrically, Q7S has lower drive strength (−4.0 mA vs. −6.0 mA for Q7) and higher VOL (0.4 V vs. 0.26 V) at V_CC = 4.5 V.

Is it safe to tie SHCP and STCP together for simplified control?

Yes, but with defined behavior: the shift register will always be one clock cycle ahead of the storage register, causing Q0–Q7 to reflect prior-shift data. This configuration eliminates timing skew between clocks but forfeits independent control of shift vs. output update - acceptable for basic serial-to-parallel conversion.

Does 74HCT594S16-13 require external pull-up resistors on its control inputs?

No. All inputs (SHR, STR, SHCP, STCP, DS) feature Schmitt-trigger action and are TTL-compatible, with VIH ≥ 2.0 V and VIL ≤ 0.8 V at V_CC = 4.5 V. Unused inputs must be tied to V_CC or GND per datasheet Note 5 - no pull-ups needed for noise immunity or logic level definition.